When your penis becomes erect when talking to a girl, but not because you're horny or want to have sex. Its an erection caused by the good feelings of having a conversation with the girl.
I really like her, but I don't think of her in a horny kind of way. When I talk to her, I get an affection erection.
A gender neutral phrase to describe the intense emotional hard-on that is stimulated through infatuation. It is one of many side effects caused by catching feelings. Infatuation ejaculation typically follows.
I have a raging affection erection burning deep within the loins of my heart .
An erection which is sprung from a deep appreciation and love for something. This kind of erection is not gender specific, and there is no need to call a doctor if said erection lasts for more than 48 hours.
I have an affection erection for cheap tacos, pizza, or burgers after a long night of drinking.